A petrol engine that transforms 1000J of chemical potential energy into 300J of kinetic energy, and 700J into wasted heat and sound energy. Calculate the Efficiency. Tysm ppl

Efficiency = 30% = 0.3

Explanation:

The general formula for efficiency of a device is given as:

Efficiency = (Desired Output / Input) * 100%

Here, in our case, we have a petrol engine as a device. So, we analyze it for the efficiency calculations. Here, we have:

Chemical Potential Energy = 1000 J

Kinetic Energy = 300 J

Heat and Sound Energy = 700 J

Now, we know that the desired output of a car or the purpose of a car is to provide Kinetic energy, while all other forms of energy such as heat and sound energies are produced as waste. And the chemical energy is provided to car as input, in form of fuel. Therefore,

Input = Chemical Potential Energy = 1000 J

Desired Output = Kinetic Energy = 300 J

Therefore,

Efficiency = (300 J/1000 J) * 100%

Efficiency = 30% = 0.3